A Fast and Sensitive Molecular Detection of Streptococcus mutans and Actinomyces viscosus from Dental Plaques

Polymerase chain reaction was used in this study in comparison with conventional method for the detection of cariogenic bacteria (Streptococcus mutans and Actinomyces viscosus) in dental plaque samples taken from two different teeth sites, a crowned tooth (tooth with crown restoration) and a natural tooth. Nested Polymerase chain reaction (N- PCR) was performed on genomic DNA which was isolated directly from plaque samples and it revealed the presence of Streptococcus bacteria and Streptococcus mutans species using two sets of 16s rDNA specific primers. Actinomyces viscosus isolates were detected also by using conventional PCR. The plaque samples were recorded negative for the presence of cariogenic bacteria, depending on conventional microbiological methods. But the same samples were recorded positive for the presence of those bacteria depending on molecular approach. This finding demonstrates that the sensitivity and specifity of the PCR techniques in the detection of the cariogenic bacteria in plaque samples are higher than the conventional culture method.